At present, underwear can be worn to effectively brace and support breasts and better outline a contour shape of the breasts by providing support components in cups and also by designing a low-heart underwear and brassiere capable of clearly presenting the shape of a cleavage portion. Such low-heart underwear or brassiere needs to be provided with a bracket capable of outlining a cleavage at the heart position, wherein, in the prior art, a semicircular support loop is arranged in two cups, which not only limits heart position but also fails to coordinate outerwear accentuate cleavage line of women very well.